1998 nissan ultima trunk release

There is no adjustment for the trunk release lever/cable. If it doesn't work there is a problem with the cable being broken/disconnected from the trunk lock assembly.

There is no need for power to open the hood. Your cable may be streached, or in need of adjustment. Have someone push down and up on hood itself while pulling the hood release lever.

Sounds like the cable from the trunk release lever( usually locaied on floor to the left side of the drivers seat) is broken.

Checked all the fuses? I assume your trunk has no key cylinder.
Can you fold down your rear seats? Many times there is a manual release inside the trunk, just incase you lock yourself in the trunk!
If there is no manual release lever or cable with handle to pull the latch itself may have a slot on it that when a flat screwdriver is inserted and twisted it will rotate the release.

You can try to remove the trunk switch and cross the two wires on the back of the switch if the switch is bad. If that does not work put 12volts to one wire and ground the other to the metal of the car. If the latch release is good it should pop open. If the solenoid on the latch is bad your going to need a lock smith.

this trunk is designed that there a position of the trunk lock that locks that inside handle,some car also use a lever at the latch to disable the inside trunk release,im 1 sure this car uses the trunk lock, take a look and see if you lock out the inside release. if the lock window where you put the key in is pointing at 3 or 9 oclock then its locked the inside release if its at 12 or 6 oclock then the inside release should work and then the cable may be bad, good luck.

should be a button or lever or pull tab somewhere along the top of your back seats that allow them to fold down..... and your trunk should have an emergency release lever inside the trunk

trunk latch cable probably needs to be replaced

If you can't glue the handle back on, e.g. with urethane glue (gorilla glue, Elmers Nano, etc.; use as directed, cleaning lever and plastic cover with soap and water just before gluing) then you can just buy a part like Nissan 84640-9E000 (1998 Altima exact replacement; Nissan call it a Handle- Trunk & Gas Door Release.)

That will work fine as long as the gas filler door mechanism isn't messed up; go check for obstructions once you open the door, presumably by using a small locking pliers over a cloth or some rubber on the lever (or the cable wire.)

The trick is, you get to replace it with the door open; use a blade screwdriver to pry the running-board trim up, unscrew the bolt on the trim to the left and pry that off, undo some expander bolts holding the carpet across the running-board area, and wrangle the carpet away from the lever you want to replace.  Some 10mm wrench work gets the lever loose, and you tilt the loosened stuff forwards to be able to remove the cable.  Regrease the bolts and cable run as well as you can.  Thread the new handle through the carpet before you bolt it in; it's harder to set up and bolt, but you don't have to cut the carpet or remove the seat!

Actually, this car has security system that prevent the trunk opened without using the master key. I often use this to lock my trunk. Just slid up the tiny lever upward to allow the trunk open from inside. the lever is on the back trunk (in the center, behind the Tail light) where the trunk door hook up with the lock system.
Cheers..